Analysis of specific cells can give insight into a variety of diseases. These analyses can provide non-invasive tests for detection, diagnosis and prognosis of diseases, thereby eliminating the risk of invasive diagnosis. For instance, social developments have resulted in an increased number of prenatal tests. However, the available methods today, amniocentesis and chorionic villas sampling (CVS) are potentially harmful to the mother and to the fetus. The rate of miscarriage for pregnant women undergoing amniocentesis is increased by 0.5-1%, and that figure is slightly higher for CVS. Because of the inherent risks posed by amniocentesis and CVS, these procedures are offered primarily to older women, i.e., those over 35 years of age, who have a statistically greater probability of bearing children with congenital defects. As a result, a pregnant woman at the age of 35 has to balance an average risk of 0.5-1% to induce an abortion by amniocentesis against an age related probability for trisomy 21 of less than 0.3%. To eliminate the risks associated with invasive prenatal screening procedures, non-invasive tests for detection, diagnosis and prognosis of diseases, have been utilized. For example, maternal serum alpha-fetoprotein, and levels of unconjugated estriol and human chorionic gonadotropin are used to identify a proportion of fetuses with Down's syndrome, however, these tests are not one hundred percent accurate. Similarly, ultrasonography is used to determine congenital defects involving neural tube defects and limb abnormalities, but is useful only after fifteen weeks' gestation
Moreover, despite decades of advances in cancer diagnosis and therapy, many cancers continue to go undetected until late in their development. As one example, most early-stage lung cancers are asymptomatic and are not detected in time for curative treatment, resulting in an overall five-year survival rate for patients with lung cancer of less than 15%. However, in those instances in which lung cancer is detected and treated at an early stage, the prognosis is much more favorable.
The presence of fetal cells in the maternal circulation and cancer cells in patients' circulation offers an opportunity to develop prenatal diagnostics that obviates the risks associated with invasive diagnostic procedure, and cancer diagnostics that allow for detecting cancer at earlier stages in the development of the disease. However, fetal cells and cancer cells are rare as compared to the presence of other cells in the blood. Therefore, any proposed analysis of fetal cells or cancer cells to diagnose fetal abnormalities or cancers, respectively, requires enrichment of fetal cells and cancer cells. Enriching fetal cells from maternal peripheral blood and cancer cells from patient's blood is challenging, time intensive and any analysis derived there from is prone to error. The present invention addresses these challenges.